The main purpose of this study is to investigate the natural history of HIV disease in women as part of a national, multi-site study sponsored by the NIH. Data will be collected on a cohort of HIV-infected women, and a comparison cohort of high-risk HIV-uninfected women. Specific research aims to be addressed in this study include the following: 1) To determine the incidence, prevalence and predictors of AIDS-defining and HIV-related conditions. 2) To determine the incidence, prevalence and predictors of clinical conditions which might be potentiated by HIV infection. 3) To determine the incidence, prevalence and clinical course of cervical neoplasia, HPV-mediated cervical disease, and genital infections. 4) To describe trends over time in substance use according to HIV serostatus and substance abuse according to immune status. 5) To determine predictors of clinical disease progression among HIV-infected women and predictors of mortality. 6) To describe the utilization of health care services and to determine predictors of health care utilization.